Impedance Analysis and Resonance Mitigation for Sample-Correction-Based Boost Power Factor Correction Converters

This letter analyzes the input impedance of digitally controlled boost power factor correction (PFC) converters, with a particular focus on the impact of current sampling. It is revealed that the use of a correction factor with current sampling brings a non-dissipative region to the input impedance of PFC converter when the load is heavy. Consequently, undesired high-frequency resonances may arise in the input current of PFC converter. To mitigate the resonance, an enhanced current-sampling correction method is proposed and validated by experimental tests.